Does any one have any suggestions to help a 7 year old boy be more focused and on task?
I can understand your concern about staying focused for a 7 year old. It's such a tough age because more is being demanded of them in school and they have a limited attention span at that age. I agree with @Joe, it's important to know when he has the most difficulty focusing. Also, it would be helpful to ask yourself: Does he have difficulty following directions? Does it take him longer to complete tasks than other kids in class? Is he often forgetful? If you answered yes to each of these, he might fall under the category of ADHD. If you think that might be the case, it would be key to talk with the school counselor and request an IEP process to see if he might fit that diagnosis.
Otherwise, if you want to wait to see about a diagnosis, you could try some ways to help with refocusing. You might try removing external stimulation, like a TV, others in the room, video games, etc. to help him focus. It would be helpful to break the task into small parts and have him check in with you throughout to make sure he's able to complete the whole task. Taking breaks in between each part can help with coming back to focus, as well. You might also try a visual timer (ideally sand timer) for him to have in front of him to know when the time is up for each task - this will also help him grasp what "time" actually looks and feels like.
Hope this helps!
The pomodoro technique is effective at helping anyone learn to focus. It is essentially a timer based approach with predefined breaks and tasks for each focus session.